Copying Column From Other Table .

There are several easy ways to accomplish what I am trying to do in a simpler way however (long story short) this is something I need to learn for a much larger task in the near future.
O.K. I have a table named clients I'm trying to get started copying columns from the same table one by one. Lets say original table has these columns:
Database kokomain -- table dbo.clients
ID(pk) fname lname idate

I've created a blank temp table with the exact same schema and named it 'temp'. I've populated the id,fname and lname fields with the statement:
Insert Into kokomain.dbo.temp (cid,fname,lname) select c.cid,c.fname,c.lname from kokomain.dbo.clients c

Now, how could I add the idate field to the table as a separate query? I've tried several variations of things like...
INSERT INTO kokomain.dbo.temp (idate) select c.idate from kokomain.dbo.clients c where c.idate in (select idate from kokomain.dbo.temp)
No dice.

The correct statement would be greatly appreciated
Thanks.